Alice

A member of the Decepticons Alice was sent to Earth to follow Sam Witwicky and retrieve information on the fragment of the Allspark. She tried to get close to him, and made sexual advances. However, Bumblebee didn’t trust her and stopped her by humiliating her.  
 
She was a very convincing human. However, when she was confronted by jealous Mikaela Banes, Alice attacked Sam in his bedroom with her long and deadly tongue; revealing she was really a Decepticon.  
 
Alice chased Sam, Mikaela and Leo across the college campus. Mikaela was forced to hot-wire a car in order to flee, but Alice leapt on top of the car as they sped along the road. Alice continued with her attack, especailly focussed on Sam until Mikaela rammed her into a light pole killing her.